The invention relates generally to semiconductor integrated circuits, and more particularly, to a spherical shaped semiconductor integrated circuit and a system and method for manufacturing same.
Conventional integrated circuits, or "chips", are formed from a flat surface semiconductor wafer. The semiconductor wafer is first manufactured in a semiconductor material manufacturing facility and is then provided to a fabrication facility, or "fab." At the fab, several layers are processed onto the semiconductor wafer surface. Once completed, the wafer is then cut into one or more chips and assembled into packages. Although the processed chip includes several layers fabricated thereon, the chip still remains relatively flat.
To own and operate a modern wafer manufacturing facility, fab, and assembly facility, tremendous resources must be assembled. For example, a single fab typically cost several billion dollars, and therefore requires a great deal of capital and commitment. This high level of capital and commitment is compounded by many problems inherent to both chips and fabs.
Many of these problems reflect on the enormous effort and expense required for creating silicon wafers and chips. For example, manufacturing the wafers requires creating rod-form polycrystalline semiconductor material; precisely cutting ingots from the semiconductor rods; cleaning and drying the cut ingots; manufacturing a large single crystal from the ingots by melting them in a quartz crucible; grinding, etching, and cleaning the surface of the crystal; cutting, lapping and polishing wafers from the crystal; and heat processing the wafers. Moreover, the wafers produced by the above process typically have many defects. These defects can be attributed to the difficulty in making a single, highly pure crystal due to the cutting, grinding and cleaning processes as well as impurities associated with containers used in forming the crystals. For example, oxygen is a pronounced impurity associated with the quartz crucible. These defects become more and more prevalent as the integrated circuits formed on these wafers contain smaller and smaller dimensions.
A problem associated with modern fabs is that they require many different large and expensive facilities. For example, fabs require dust-free clean rooms and temperature-controlled manufacturing and storage areas to prevent the wafers and chips from defecting and warping. The amount of dust in the clean rooms is directly proportional to the end quality of the chips. Also, warping is especially problematic during heat treatment processes.
Other problems associated with modern fabs result from their inherently inefficient throughput as well as their inefficient use of silicon. For example, modern fabs using in-batch manufacturing, where the wafers are processed by lots, must maintain huge inventories to efficiently utilize all the equipment of the fab. Also, because the wafers are round, and completed chips are rectangular, the peripheral portion of each wafer cannot be used.
Still another problem associated with modern fabs is that they do not produce chips that are ready to use. Instead, there are many additional steps that must be completed, including: cutting and separating the chip from the wafer; assembling the chip to a lead frame which includes wire bonding, plastic or ceramic molding and cutting and forming the leads, positioning the assembled chip onto a printed circuit board; and mounting the assembled chip to the printed circuit board. The cutting and assembly steps introduce many errors and defects due to the precise requirements of such operations. In addition, the positioning and mounting steps are naturally two-dimensional in character, and therefore do not support curved or three dimensional areas.
Therefore, due to these and various other problems, only a few companies in the world today can successfully manufacture conventional chips. Furthermore, the chips must bear a high price to cover the costs of manufacturing, as well as the return on initial capital and investment.